A new study has aimed to simulate how SARS-CoV-2, the virus that causes Covid-19, may spread across surfaces in a hospital.
For safety, the researchers did not use the SARS-CoV-2 virus but artificially replicated a section of DNA from a plant-infecting virus, which cannot infect humans.
The virus DNA left on a hospital bed rail was found in nearly half of all sites sampled across a ward within 10 hours and persisted for at least five days.
Researchers placed the water containing the DNA on the hand rail in an isolation room, a room for higher-risk or infected patients, and then sampled 44 sites across a hospital ward over the following five days.
They found that after 10 hours, the surrogate genetic material had spread to 41% of sites sampled across the hospital ward, from bed rails to door handles to arm rests in a waiting room to children’s toys and books in a play area.
The highest proportion of sites that tested positive for the surrogate came from the immediate bed-space area – including a nearby room with several other beds – and clinical areas such as treatment rooms.
SARS-CoV-2 will likely be spread within bodily fluid such as cough droplets, whereas the study used virus DNA in water. More sticky fluid such as mucus would likely spread more easily.
While it shows how quickly a virus can spread if left on a surface, it cannot determine how likely it is that a person would be infected.
The study shows the important role that surfaces play in the transmission of a virus and how critical it is to adhere to good hand hygiene and cleaning.
The sample was inoculated once to a single site, and was spread through the touching of surfaces by staff, patients and visitors. A person with SARS-CoV-2, though, will shed the virus on more than one site, through coughing, sneezing and touching surfaces.